Burden of COVID‐19 disease in Kurdistan province in west of Iran using disability‐adjusted life years

Abstract Background and Aims During the coronavirus disease 2019 (COVID‐19) pandemic, about seven million people were infected with the disease, of which more than 133,000 died. Health policymakers need to know the extent and magnitude of the disease burden to decide on how much to allocate resources for disease control. The results of this investigation could be helpful in this field. Methods We used the secondary data released by the Kurdistan University of Medical Sciences between February 2020 to October 2021 to estimate the age‐sex standardized disability‐adjusted life years (DALY) by the sum of the years of life lived with disability (YLD) and the years of life lost (YLL). We also applied the local and specific values of the disease utility in the calculations. Results The total DALY was estimated at 23316.5 and 1385.5 per 100,000 populations The YLD and YLL constituted 1% and 99% of the total DALY, respectively. The DALY per 100,000 populations was highest in the men and people aged more than 65 years, but the prevalence was the highest in people under the age of 40. Conclusions Compared to the findings of the “burden of disease study 2019,” the burden of COVID‐19 in Iran is ranked first and eighth among communicable and noncommunicable diseases, respectively. Although the disease affects all groups, the elderly suffer the most from it. Given the very high YLL of COVID‐19, the best strategy to reduce the burden of COVID‐19 in subsequent waves should be to focus on preventing infection in the elderly population and reducing mortality.


| INTRODUCTION
The coronavirus disease 2019 (COVID- 19) pandemic has spread in the world and has become a serious challenge for governments and health systems, so that countries have experienced several waves of this disease so far. 1,2 As of February 14, 2022, the new coronavirus has infected more than 413 million people and killed 5.8 million people worldwide. The coronavirus pandemic was the second leading cause of death in Oceania, the third in North America and the 19th leading cause of death in Asia. 3,4 Iran is also one of the countries most affected by the virus, so that to date, the virus has infected more than 6.8 million people and killed more than 133,000 people. 3,4 In addition to the epidemiological burden, the COVID-19 pandemic has imposed a significant economic burden on countries around the world. Thus, in 2020 alone, it led to the loss of 6.65% of GDP in the world, and if the pandemic continues, this amount will reach 48% in 2020-2030. 5 Low-and middle-income countries, due to lack of adequate financial support, are unable to support the vulnerable and this has led to a poorer society and an increase in the death rate from COVID-19. 6,7 However, little is known about the socioeconomic impact of COVID-19 in low-and middle-income countries. 8,9 To estimate these effects, DALYs can be a useful tool. 10,11 This index shows the rates of premature death and the inability caused by the disease to quantify the burden of the disease. 12 DALYs, which is one of the adjusted life expectancy indicators, is an indicator for COVID-19 to judge the success of preventive and curative interventions in health systems, allowing policymakers to make standard comparisons between different health systems. In addition, this index determines the extent and rank of the epidemiological burden of the disease in comparison with other common diseases within any health system. 13,14 Utilizing the results of burden of disease studies will lead to optimal and cost-effective decisions that will benefit society the most. 15 Researchers have calculated the burden of the epidemiological disease of COVID-19 for some countries. These calculations are different in terms of the value of the disease utility (specific/ nonspecific), the extent of the geographical area (international/ national/regional/provincial), and the period of the study (the first or second wave of the disease/the entire period of the disease). These differences have made the disease burden of COVID-19 not only dependent on the prevalence of the disease but also affected by the study methodology. So the results cannot be directly compared with each other. [16][17][18][19][20][21][22][23][24][25][26][27] In addition, studies conducted in the United States 28 and Japan 29 have investigated the effect of the outbreak of the COVID-19 pandemic on changes in out-of-hospital cardiac arrest and other vaccine-preventable diseases DALYs, respectively.
The aim of this study was to describe and estimate the epidemiological burden of COVID-19 in Kurdistan province in west of Iran. What sets this study apart from other studies is the use of the COVID-19-specific disability weight. 30 For the first time, this study has calculated the burden of COVID-19 disease in Iran using local and specific disability weight values of this disease, which informs health policy makers about the extent of the disease in comparison with other communicable and noncommunicable diseases. The findings of this study can determine the position of the COVID-19 disease in the country and provide enough justification for allocating sufficient funds and resources to control this vaccine-preventable disease burden.

| Study design and participants
This retrospective descriptive epidemiological study was conducted at Kurdistan province, in the west of Iran, covered all laboratory-confirmed cases during February 2020 to October 2021. This border province has an area of 29,137 square kilometers and a population of more than 1.6 million people. About a third of this population lives in rural areas. 31 In accordance with the World Health Organization (WHO) recommendations, we defined people with COVID-19 disease as having a positive reverse transcriptase polymerase chain reaction (RT-PCR) and included data from all laboratory-confirmed cases during the study period. According to the recommendations of the WHO, qualitative real-time RT-PCR nasopharyngeal swab which detects the presence of specific segments of the SARS-CoV-2 genome is the gold standard method for diagnosing  disease. This diagnostic approach has high specificity but moderate sensitivity of 50%-62%. 32 Therefore, the presence of substantial false negatives confirms that the confirmed cases are significantly less than the actual cases with COVID-19.
According to the national protocols, RT-PCR test is taken from the suspected cases. These cases are people who have one or more signs and symptoms of the disease including fever, cough, general weakness/fatigue, headache, myalgia, sore throat, coryza, dyspnea, anorexia/nausea/vomiting, diarrhea, and altered mental status or those have been in close contact with the infected people for the past 14 days, including all people who have lived with them.

| Data collection
We gathered data on COVID-19's outpatients from the Deputy of This data is collected daily from testing centers and designated hospitals for the management of patients with COVID-19 and aggregated in the mentioned deputies. We considered 14 days as the average quarantine time at home for the outpatients and discharged patients according to the national protocol.

| Modeling
Using DISMOD 11 software, 33  Where YLDs equals the sum of years spent with disability due to COVID-19 disease. Disability is defined as reduced HRQoL attributed to the diseases. 30 To calculate YLDs, the annual equivalent of number of days spent with the disease is multiplied by the value of the disease disutility (=1-utility). The disease duration was equal to the time interval between the onset of symptoms or signs until complete recovery or before death. 15 Finally, the sum of YLDs obtained for each infected person showed the number of YLDs in the community.
Also, YLLs metrics were calculated by taking the product of the number of deaths from age-sex-specific estimates of mortality by COVID-19 disease. Estimated Iranian life expectancy was obtained from WHO statistics. 34 The YLLs were summed across age categories to determine total YLLs. Due to the fact that the COVID-19 disease has a different effect on young, middle-aged, and the elderly, we have presented the results in terms of three age groups of under 40, 40-65, and over 65 years.
According to the findings of our previous study, the health status of patients with the COVID-19 is divided into four groups based on the severity of the disease, which determines the level of health-related quality of life: Quarantine at home, general wards hospitalization, ICU hospitalization with no intubation, and ICU hospitalization with intubation.
Using the time trade-off approach, the average utility values of these patients were estimated as 0.896, 0.847, 0.766, and 0.629, respectively. 30

| RESULTS
The total number of confirmed cases during the study period was 53550 people, including 33  DALYs on the population of the province (Table 2).

| DISCUSSION
The COVID-19 pandemic has significantly reduced the well-being of communities by imposing significant epidemiological and economic burdens on countries, and today the disease is considered to be one of the leading causes of death. [35][36][37] However, the epidemiological effects of the disease are not limited to death; the morbidity has also placed many limitations on the patient's health-related quality of life and those around them. [38][39][40][41][42] In our previous study, 30 Tables 3 and 4 are presented to better understand the epidemiological burden of COVID-19 and the resulting pressure on the Iranian health system. Table 3 shows the adjusted burden of disease per 100,000 population for a number of noncommunicable diseases with the highest DALYs at national level based on the GBD study, 2019. 43 As can be seen in this Table, the burden of COVID-19 disease is in the eighth place compared to other diseases (Table 3). Table 4 presents the adjusted burden of disease per 100,000 population for a number of communicable diseases with the highest DALYs at national level based on the GBD study in 2019. 43 As can be seen in this  46 and it were more than 98% in another studies in 16 European countries, 13 in India, 22 in Colombia, 18 in Germany, 21

| Strengths and limitations
It is important to bear in mind the possible bias in the findings. The study data was only related to cases with positive PCR test and did not covers those with false-negative tests and infected people who did not give any diagnostic tests. So, obtained DALY value may be underestimated. To overcome this severe uncertainty, we performed a one-way sensitivity analysis over the key factors including

| CONCLUSION
To know the extent, burden, and rank of COVID-19 among all diseases, we conducted this study using the comprehensive data of patients registered during the entire pandemic period and also using specific and local values of the disease's utility and we were able to provide a valid understanding of the disease epidemiological burden. writing-original draft.

ACKNOWLEDGMENTS
The authors would like to thank the persons who participated in this study. This study was funded by Kurdistan University of Medical Sciences with contract number 1399.077. However, there was no role of the funding body in the study design; collection, analysis, and interpretation of data; writing of the report; or the decision to submit the report for publication.

CONFLICT OF INTEREST STATEMENT
The authors declare no conflict of interest.

DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author (Bakhtiar Piroozi) upon reasonable request.

ETHICS STATEMENT
This study was approved by ethics committee of Kurdistan University of Medical Sciences with the code IR.MUK.REC.1399.077. Participation in the study was voluntary and written consent was obtained from the participants.